Reversible galvanic battery.



TATENTED DBG. 1o, 19o?` y T. A. EDISON. ...REVERSIBLE GALTANIG BATTERY.

APPLIOATION FILED NOV.23,19'03.

Jzzenar MJ.. f.

i THOMAS A. EDISON, OF LLEWELLYN PARK, ORANGE, NEW,

STORAGE BATTERY COMPANY, OF ORANGE,

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To all 'whom it may concern:

Beit known that I, THOMAS A. EDISON, of Llewellyn Park, Orange, in the county of Essex and State of `New Jersey, have invented certain Improvements in Revers'ibleGalvanic Batteries, ofwhich thefollowing is a specification. 'l l My invention relates to improvements in reversible galvanic batteries 'of 'the ltype invented by. me wherein nickelhydroxid is opposed to finely-divided electrolyticallyt active iron in an alkaline solution. l

l My object is to im rove the output of such batteries, and to re u ce the sw elling of 'the depolarizing mass in the nickel-plated perforated pockets in which it is maintained under pressure.

Reference is herebymade to the accompanying drawing of which Figure 1 is a side view 'of a fragment of ya storage batteryl grid in which one of the perforated pockets is held, and Fig. 2 is a section on line 2 -2 of Fig. 1 'on' a greatly enlarged scale. proportion (say 15 per-eceiit.) of bismuth 'hydroxid is intimately mixed with nickelhydroxid and applied tothe surfaces' of :flakes of an inert, insoluble conducting material, such as4 Hake graphite, very' superior results vare obtained, the total capacity per unit of weight of the mixture bein greater than when the same-Weight of nic el hydroxid is used alone, and the swelling of the two hydroxids together being less vthan when the same weight of nickel is used alone. I am unable at this time to explain the reason why these superior results are obtained, but the advantages are nevertheless derived.

The mixture of ac tiveamaterials vis preferably em loyed under pressure in 'perfo-.

rated meta lic pockets 2 as I have described in patents heretofore granted, and when so used, the reduction of the swelling becomes very important. or oxidizable electro e may be used, having an insoluble active material, vsuch asiiron or Icobalt', o1-having a soluble active material like zinc which dissolves inthe solution during discharge, being plated, out (inthe succeed ingcharg'ingoperation." 'Preferably-,howef'ver the negative pole electrodefflfliilizs nelyf Specification of Letters Patent. Application filed November zaisos.- serial No. 182,429.

I have discovered thatv whena small A'n `suitable negative pole NEW JERSEY, A CORPORATION OF NEW- REVERSIBLE GALVANIG BATTERY.

divided electrolytically-active iron .to which is preferably added a readily reduciblemetal (such as mercury, silver or copper), the whole being maintained under pressure lin perforated pockets secured in suitable ids. In making the improved electrodes 'prefer to precipitate the ytwo hydroxide together from their dissolved salts, as in this Wa'y .a very intimate mixture of the two is secured. The precipitated hydroxidsare Washed free of impurities, and While in a moist condition are intimately mixed with a flake-like inert conducting material, preferably flake-graph? ite. This mixing is most effectively secured in a Chilean mill, the rollers of which are not heavy 'enough to pulverize the graphite flakes, and the mixing is continued until the mass is uniformly dark, and presents the a pearance of graphite alone.

In this con y Patented Dec. 1o,1eo'7l JERSEY, AssIGNoR "ro EDISON tion the mixture of nickel and bismuth hy'- droxids will be distributed as extremely thin filmsover the surfaces of the graphite Hakes,

4'and will be in the most Aeffective condition.

The mixture is now applied Within' erfoiated pockets as heretofore explains ,l secured within openingsinsuitable grids, or an other mechanical arrangement may be utilized to support the active mass.

The negative'pole or oxidizable electrodemay be made in any suitable Way, such as I v'have pointed out in former patents, and pref' erably utilizes as its active mass, a Ir'iixture of electrolytically-active finelydivided iron and mercury. The 4two electrodes are now immersed in an alkaline solution, such as per cent. solutionlof potassio hydrate,

a 20 and t e cell will then be ready for use.'4 In charging the bismuth and nickel hydroxisd will be raised to a 'high condition of oxidation,

the iron beingreduced to the metallic. state. y

Whenthe cell is reversed, the iron will be oxidized to a low condition of oxidation, and, f

Vthe hydroxids will be reduced to lower hydroxids. The proportion 4of'bis'muth vliydroxid, usedmay bevaried Within quite Wide limits, but.. excellent-'results have 'been seciired when about 15 per cent. `by weight o f bismuth Ahydri'ixid and 85 per cent. by Weight iofnickel hydroxid havebeen" used. It may sive' "character vo` qltientity of bismuth hydroxid should be used t iat Will'gi've the required results under the desiredl conditions.l

` Having now described my invention, what I claim as new therein and desire to secureby ALetters Patent, is as follows:

1. A depolarizing electrode for reversible galvanic batteries, containing a.' mixture of nickel hydroxidand bismuth hydroxid the proportion of the latter ingredient being much smaller than that of the former, substantially as set forth.

2. A depolarizing electrode for reversible 3. A depolarizing electrode for reversible galvanic batteries, containing a, mixture of nickel hydroxidandv bismuth hydroxid, sind en inert fieke-like conducting,materiel` on the surfaces of which the mixture is carried in the form of Very thin films, substantially as set forth.

4; In a reversible gelvnnic. battery, :in :ilkaline electrolyte,e depolerizing electrode -containing; at mixture of nickel hydroxid und bismuth hydroxid the pro )ortion of the latter invredient being lnucli snmller than that of the former, and an oxidizable electrode, substantiall es set forth.

5. In a reversib e galvanic buttery, un :tlkaline electrolyte, n depolerizing electrode containing a mixture of nickel hydroxid und bismuth hydroxid the proportion of the lutter ingredient being much smaller than tlnit of the former, and an oxidizeble electrode, containing finely divided electrolyticnlly activo iron, substantially as set forth.

This specification signed and witnessed this 20th dey of Nov. 1903.

THOS. A. EDISON.

Witnesses g FRANK L. DYER, W. G. BEE. 

